Tapeworm Cancer Growing In A Human

H. nana tapeworm

In 2015, a man was found to have 'cancer' growing in him, but the cancer cells were not his. His 'cancer' cells were found to have come from tapeworms living in his body. The tapeworm cells had invaded his tissues and formed  tumorous growths.  The man was already very sick and weakened due to infection with HIV, and it is thought that his body was not able to fight off the invading worm cells.

Image Credit
Wikimedia Commons https://commons.wikimedia.org/wiki/File:The_diseases_of_infants_and_children_(1919)_(14780207951).jpg